Applicator for particulate material



March R. F

APPLICATOR FOR PARTICULATE MATERIAL File d May 4, 1966 INVENTOR RALPH FRY T R Y United States Patent 3,434,758 APPLICATOR FOR PARTICULATE MATERIAL Ralph Fry,'Warren, Pa., assignor to Ferro Corporation, Cleveland, Ohio, a corporation of Ohio Filed May 4, 1966, Ser. No. 547,618 Int. Cl. B65g 53/42; Bb 3/08 US. Cl. 302-61 4 Claims ABSTRACT OF THE DISCLOSURE For as long as cast iron sanitary ware such as bathtubs, lavatories and sinks have been coated with vitreous porcelain enamel, the process has usually been carried out by heating the casting to be coated to a temperature of from approximately 1400 to 1700 F., withdrawing the casting from the heating furnace, placing same in a cradle adapted to be tilted through a 90 arc and rotatable 360, with an operator standing over the hot casting manually sifting powdered porcelain enamel onto the heated article the while it is manipulated in its cradle to present various surfaces to the cascading material.

The heat of the base metal caused the porcelain enamel coming in contact therewith to fuse and adhere thereto, and the process was repeated, with reheating of the casting, two or three times until a sufliciehtly thick coating of vitreous enamel had been built up on the surface of the article, to thereby provide a protective coating having a pleasing smooth appearance, and high degree of chemical resistance.

The casting, following the above procedure, was then allowed to cool during which the vitreous coating be came quite hard and glassy and the article was ready for distribution and installation.

However, one of the drawbacks to the conventional method of manually sifting powdered porcelain enamel onto a hot casting is that rising costs have rendered the manual operation prohibitively expensive.

Too, manual sitting of powdered enamel onto a hot casting to secure. proper and even distribution thereof is a highly skilled art, thus resulting in an extremely high wage scale for the skilled operator, as well as necessitating a rather lengthy training period for him. This, plus the fact that the absence of an operator for several days through sickness or otherwise severely hampers production, militates toward substitution of mechanized means for the traditional hand method of coating.

Finally, the hand shifting method, which relies on gravity to transport the powdered particulate material to the substrate to be coated is limited in its rate of application thus resulting in an excessively long period of time being required for adequately covering a predetermined area.

Numerous methods have been tried for getting the particulate material to the substrate, included among them being electrostatic deposition and various nozzle means for blowing powdered porcelain enamel directly onto the ware to be coated.

However, the electrostatic means requires rather expensive and intricate equipment, the use of which pre sents problems in coating the rather complex contours of a bathtub or lavatory, particularly in view of the rather 3,434,758 Patented Mar. 25, 1969 strong air currents created in the vicinity of an extremely hot mass such as a bathtub at 1600 F.

The use of compressed air for directly blowing powdered enamel onto a hot workpiece, on the other hand, has met with very little success because the rather high volume of high pressure air impinging directly onto the red hot casting has a tendency to cause localized cold spots which interfere with the proper, even fusion of the enamel.

Accordingly, it is an object of this invention to provide an apparatus for the directional deposition of particulate material onto a predetermined area.

It is further an object of this invention to provide an improved apparatus for the directional deposition of particulate, powdered porcelain enamel to a cast metal substrate.

It is a further object of this invention to provide a new and improved apparatus for the directional deposition of powdered porcelain enamel to a heated, cast iron piece of sanitary ware.

The invention is demonstrated by the attached drawings wherein:

FIG. 1 is a schematic layout of the complete apparatus;

FIG. 2 is a spinner for deposition of the particulate material; and

FIG. 3 is a variable form of the spinner depicted in FIG. 2.

Referring now specifically to the attached drawings, in FIG. 1 the reference numeral 1 indicates a fluidized bed source of powdered porcelain enamel 2.

The source consists of an upper chamber 3 and a lower chamber 4 separated by a perforate diaphragm 5, the lower chamber 4 being connected to a source of compressed air (not shown) via tubing 6.

By means well known in the art, compressed air entering lower chamber 4 via tubing 6 passes upwardly through the perforate diaphragm 5 and literally flu-idizes the powdered porcelain enamal in the upper chamber 3, and by a method furthermore well known in the art, the particulate fluidized material is forced out of source 1, in its fluidized state, via flexible duct 7, the other end of which is open to the atmosphere as will be hereinafter explained in greater detail.

Flexible duct 7 is joined to a rigid tubular member 8 at juncture 9, by any suitable means, the other end of rigid tubular member 8 being connected to a curved deposition nozzle 10, which opens into the atmosphere within the interior of funnel-shaped spinner 11.

Spinner 11 is fixed to shaft 12 as shown, spinner 11 and shaft 12 being rotatable about a common axis of rotation, and journalled at point 13 is bracket 14 which in turn is fixed to rigid tubular member 8.

15 is a conventional air motor connected to a source f compressed air (not shown) via flexible tubing 16, said air motor being fixed to rigid tubular member 8 by brackets 17 and 18.

The entire assembly, if it is to be a portable type apparatus adaptable to be manipulated by one man, can then be lifted by member 19 fixed by suitable brackets to the entire assembly, which serves as a handle for manipulation and control of the apparatus.

Although not shown, air motor 15 has a conventional controllable shut-off which is readily accessible to the operator and which enables him to activate spinner 11 at will. At the same time, source 1 of the powdered material can also be controlled by a suitable valve at any point along flexible tube 7, preferably in the vicinity of its juncture 9 with rigid tubular member 8, to stop the flow of particulate material through the assembly.

If desired, a double acting valve arrangement may be employed to simultaneously stop both the spinner and the flow of powdered enamel through the assembly.

In operation, the system is activated by admitting cornpressed air via tube 6 to the source of particulate material, and via tube 16 to the air motor, with the result that a continuous flow of powdered material is directed toward the vortex of spinner 11, which, spinning at a rate of a minimum of 100 rpm. throws the particulate material outwardly for several feet in a direction generally opposite to that in which it entered the funnel-shaped spinner. Discharge of the powdered material from the spinner is in the form of a fog, which can be directly at will by simply manipulating the entire assembly.

By funnel-shaped, as applied to spinner 11, is meant any circular taper leading to an opening such as generally bell-shaped, or bowl-shaped, the latter variation of the funnel-shaped spinner depicted in FIG. 3.

The slope and depth of the wall of spinner 11 may be varied in order to lengthen or shorten the fog stream emanating therefrom, and a degree of control over the intensity, length and concentration of the enamel within the fog stream may be maintained by the installation of vanes 20 along the interior surface of the spinner.

Too, it is contemplated that a multiplicity of the apparatus as depicted could be mobilely arranged on an assembly line at various stations so that, as a hot piece of sanitary ware, such as a bathtub, were advanced along an assembly line, the various pieces of deposition apparatus could be tilted, turned and rotated, with on and off programming, to mechanically deposit powdered porcelain enamel to the desired areas of the piece to be enameled, without the need for any manual labor.

While curved nozzle 10 of my apparatus is so disposed to deposit powdered enamel along a line parallel to the axis of rotation of the spinner 11, depending upon the deposition pattern desired, the nozzle 10 may direct its powdered enamel within said spinner at an angle with its axis of rotation up to, but not exceeding, 45 therewith.

Too, while I have shown an air motor 15 for rotating spinner 11, it is understood that any suitable, conventional means of rotating spinner 11 at a constant, controllable and predetermined r.p.m. would be acceptable as a substitute for air motor 15.

Also, while I have found the fluidized-bed pneumatic system of floating and transporting particulate material to the spinner to be preferred and best suited for my purpose, it is also contemplated that any conventional and eflective means of controllably transporting a predetermined volume of particulate material to within the spinner of this invention would suffice as a substitute for the apparatus shown.

The crux of this invention therefore resides in the introduction of a constant and substantiall continuous flow of powdered material into the approximate vicinity of the vortex of a rotating spinner adapted to hurl the particulate material outwardly in a direction generally opposed to that in which the particulate material entered the spinner.

My novel apparatus thus providing a means for controllably and directionally applying particulate material to a substrate, utilizing compressed air for the transportation of the particulate material up to a certain point, but final deposition being achieved by mechanical means.

The big problem thus being overcome by my device is that introduced by a concentrated, high pressure jet of compressed air directed toward the piece to be coated, thereby causing excessive and localized cooling. Utilizing my invention, relatively low volume, low pressure, air is used to get the powdered material to the spinner, which provides the sole motivating force in throwing the particulate material outwardly to achieve the final coating step, it being understood that the volume and pressure of air being utilized to deliver particulate material to spinner 11 would not suflice for directly applying the particulate material to the substrate to be coated.

That is, the low level volume and pressure of air utilized to carry the particulate material to the spinner, is just suflicient to transport the particulate material to the spinner at a constant and uniform rate, and does not deposit the powdered material within the spinner with anything approximating the force with which the spinner then throws the particulate material onto the piece to be coated. And, what air is directed into the spinner is quickly dissipated, never impinges directly on the hot casting to cause undesirable, localized cooling.

Summarizing then my invention comprises an apparatus for dispersing dry, particulate material comprising a source of particulate material, a rotatable, generally funnel-shaped spinner having an axis of rotation and a flared opening, said spinner having vanes disposed therewithin, means for rotating said spinner, said source of particulate material residing in an air fluidized bed communicating with said spinner via a duct extending from said source to a point within the interior of said spinner, said particulate material adapted to be air entrained and transported through said duct under the influence of said air fluidization from said source thereof, to said spinner, said duct terminating in an ejection end within said spinner disposed to directionall introduce said air entrained particulate material substantially continuously to the interior of said spinner, via its flared opening, along a line lying between about 0 and 45 with the axis of rotation of said spinner, said spinner adapted to be rotated at a speed sufficient to throw said material outwardly in a direction generally opposed to its direction of introduction to Within said spinner.

Wherefore, having described my apparatus in detail as required by the governing patent statutes and case law, I claim:

1. Manually directional apparatus for dispersing dry, particulate material comprising a source of particulate material, a rotatable, generally funnel-shaped spinner having an axis of rotation and a flared opening, said spinner having vanes disposed therewithin, means for rotating said spinner, said source of particulate material residing in an air fluidized bed communicating directly with said spinner via a continuous duct member extending from below the surface of said source to a point within the interior of said spinner, said particulate material adapted to be air entrained and transported through said duct under the influence of said air flu-idization from said source thereof, directly to said spinner, said duct terminating in an ejection end within said spinner disposed to directionally introduce said air entrained particulate material substantially continuously to the interior of said spinner, via its flared opening, along a line lying between about 0 to 45 with the axis of rotation of said spinner, said spinner adapted to be rotated at a speed sufiicient to throw said material outwardly in a direction generally opposed to its direction of introduction to within said spinner.

2. Manually directional apparatus for dispersing dry, particulate material comprising a source of particulate material, a rotatable, generally funnel-shaped spinner having an axis of rotation and a flared opening, said spinner having vanes disposed therewithin, an air motor connected to said spinner via a shaft for rotating said spinner, said source of particulate material residing in an air fluidized bed communicating directly with said spinner via a continuous duct member extending from below the surface of said source to a point within the confines of said spinner, said particulate material adapted to be air entrained and transported through said duct under the influence of said air fiuidization from said source thereof directly to said spinner, said duct terminating in an ejection end within the interior of said spinner, disposed to directionally introduce said air entrained particulate material substantially continuously within the confines of said spinner, via its flared opening, along a line lying between about 0 and 45 with the axis of rotation of spinner, said spinner adapted to be rotated at a speed sufiicient to throw said material outwardly in a direction generally opposed to its direction of introduction to within said spinner.

3. Manually directional apparatus for dispersing dry process, powdered porcelain enamel comprising a source of said powdered porcelain enamel, a rotatable, generally funnel-shaped spinner having an axis of rotation and a flared opening, said spinner having vanes disposed therewithin, an air motor connected to said spinner via a shaft for rotating said spinner, said source of particulate material residing in an air fluidized bed communicating directly with said spinner via a continuous duct member extending from below the surface of said source to a point within the interior of said spinner, said powdered porcelain enamel adapted to be air entrained and transported through said duct under the influence of said air fiuidization from said source thereof directly to said spinner, said duct terminating in an ejection end Within said spinner disposed to directionally introduce said air entrained powdered porcelain enamel substantially continuously within the confines of said spinner, via its flared opening, along a line lying be tween about 0 and 45 with the axis of rotation of said spinner, sa-id spinner adapted to be rotated at a speed sufficient to throw said enamel outwardly in a direction generally opposed to its direction of introduction to within said spinner.

4. Manually directional apparatus for dispersing dry process, powdered porcelain enamel comprising a source of said powdered porcelain enamel, a rotatable, generally funnel-shaped spinner having an axis of rotation and a flared opening, said spinner having vanes disposed therewithin, an air motor connected to said spinner via a shaft for rotating said spinner, said source of particulate material residing in an air fluidized bed communicating direct- 1y with said spinner via a continuous duct member extending from below the surface of said source to a point within the interior of said spinner, said powdered porcelain enamel adapted to be air entrained and transported through said duct under the influence of said air fluidization from said source thereof directly to said spinner, said duct terminating in an ejection end Within said spinner disposed to directionally introduce said air entrained powdered porcelain enamel substantially continuously within the confines of said spinner, via its flared opening, along a line lying between about 0 and with the axis of rotation of said spinner, said spinner adapted to be rotated at a minimum of r.p.m. to throw said enamel outwardly in a direction generally opposed to its direction of introduction to within said spinner.

References Cited UNITED STATES PATENTS 45,974 1/ 1865 Chambers. 1,585,990 5/ 1926 Houghton 118-308 XR FOREIGN PATENTS 686,283 5/ 1964 Canada.

WALTER A. SCHEEL, Prmary Examiner.

R. L. SMITH, Assistant Examiner. 

